Radiator redo

The Glitch:

An installer is asked to assess a system in which an aging steam boiler supplies several cast-iron radiators. After inspecting the radiators, he proposes to convert the system from steam to hot water and replace the old boiler with a mod/con boiler. The installer pipes in the new boiler to the existing black iron piping system as shown in Figure 1, and installs thermostatic radiator valves (TRV) on each radiator to provide room-by-room zone control. The circulator is wired to run continuously during the heating season. Although the installer’s intentions are good, can you spot some potential problems with the make-over and suggest some improvements?

Are you an ace troubleshooter?

Within the pages of this magazine, PM’s Hydronics Editor John Siegenthaler, P.E., will pose a question to you, our readers, to review a system’s schematic layout and discover its faults, flaws and defects. Discover archived “The Glitch & The Fix” exercises at its radiant-focused website, www.radiantandhydronics.com. Good luck!